A human hand has a complex anatomy composed of five digits (four digits and an opposable thumb) having twenty-seven bones (fourteen phalanges (proximal, middle or intermediate, and distal), five metacarpals, and eight carpals), joints, ligaments/tendons, muscles, arches (longitudinal, transverse, and oblique), soft tissue, skin folds/webs, nerves, and vascular anatomy.
Furthermore, the human hand includes an anterior surface (palm) and posterior surface (dorsal) that are shaped by the arches of the hand to create a hollow cavity which changes shape during hand movements. For instance, the shape of the hollow cavity created by the hand arches changes shape with the hand grasps an object and my change differently based on the size of the object grasped.
Hand anatomy allows for manipulation of a multitude of different objects but this also makes it susceptible to musculoskeletal diseases, nerve disorders, vibration, bone bruises, blisters, fatigue, and/or other discomfort because of the lack of opposition in the skin folds/webs, natural gaps created at the joints and skin creases between the hand and the grasped object. This is particularly true when a user must grip and manipulate a tool with a handle (e.g., ax, hammer, shovel, baseball/softball bat, lacrosse stick, rowing oar, or the like). In these instances, the user must exert maximum gripping effort with their hand(s) to maintain control the tool because of the lack of support within the thumb web area of the hand, potential limitations of the handle design to optimize grip span, and the rotational forces and push/pull forces required to properly manipulate the tool. However, the repetitive maximum gripping effort and natural oscillation of the handle within the hand may result in various injuries to the hand such as musculoskeletal injuries, carpal tunnel syndrome, blisters and/or bruises caused by repetitive force, impact, and vibrations transferred to the hand when the tool contacts an object (tree, nail, ball, or the like). Furthermore, the generally round shape of tool handles does not provide an ideal shape and/or size (e.g., diameter, circumference) for maximizing a relaxed grip while allowing maximum tool control and accounting for rotational forces, grip span and/or user comfort. In addition, the human hand does not have the needed support because the hand shape and anatomy (e.g., incompressibility) naturally lacks an oppositional force to maximize the rotational movement that round handle shapes required to provide the ideal leverage point needed for maximizing the efficiency, control, power, speed, and/or strength of a user manipulating the tool.
One solution that others have attempted is to create a gripping aid which reduces the hand-to-handle friction in order to reduce the movement of the handle within the hand. However, these attempts ignore the anatomy of the human hand and the natural movement (e.g., oscillation) needed to efficiently manipulate of a handle.
In another solution others have attempted is to apply ergonomic grip science directly to the handle or tool to update the handle design in an attempt to increase comfort and usability. However, these attempts to alter the handle design are deficient since: 1) they cannot account for the specific anatomy (e.g., palm or finger size, high or low hand arches, an amount of soft hand tissue, grip span length, etc.) of the user's hand and therefore, lack user customization; 2) render the tool less functional since the handle design requires that the tool be manipulated in a specific manner; and 3) do not reduce vibration, bone bruises, and skin abrasions, etc.
As such, there remains a need for a comfortable gripping aid that utilizes grip arch performance technology with dual arch design to provide ergonomic grip span customization to a user's hand and orthotic support for biomechanical enhancement. Furthermore, there remain a need for a gripping aid that provides a combination of stability and instability (e.g., by promoting the natural oscillation of the hand-to-handle interface and increasing friction of the handle within the hand) which is more reflective of the natural hand movement and creates grip efficiency. Such a gripping aid also minimizes potential damage to a user's hand(s) by reducing vibrations, bone bruises, blisters and fatigue, while simultaneously providing a fulcrum to maximize the efficiency, control, power, speed, and/or hand strength as the user manipulates the tool.